<!DOCTYPE html>
<html lang="zh-CN">
  <head>
    <meta charset="UTF-8" />
    <title>Hello World 按钮示例</title>
    <script>
      function showHelloWorld() {
        document.getElementById("message").textContent = "Hello World";
      }
    </script>
  </head>
  <body>
    <button onclick="showHelloWorld()">点击显示 Hello World</button>
    <div id="message" style="margin-top: 10px"></div>
  </body>
</html>
